The vast majority of journalists are Liberals. They donate to Democrats and Liberals causes. They report in a bias fashion that favors Democrats and demonizes Republicans.
The day the media takes a middle road, give both Republicans and Democrats equal Hell in reporting without favor to either party, that will be the time their credibility with the public will be fully restored.
Will they do it? I doubt it very much and as such the public will continue to hold them in very low regard, and not take ABC, CBS, NBC, or CNN seriously at all.